This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. One of the goals of the proposed investigation is to determine whether the activity of hepatic CYP2B6 in hydroxylation of bupropion changes with the onset of pregnancy and with gestational age. The hydroxylation of bupropion in non-pregnant women indicated wide variability in its pharmacokinetics. The information on the effects of bupropion on the pregnant woman and the developing fetus is scarce thus precluding its consideration for clinical trials in this patient population. Therefore, to achieve this goal the use of an animal model is required due to ethical and safety considerations. Each baboon will receive an oral single dose of bupropion during First (between 40-54 days of gestation), second (between 94-108 days) and third (between 142-156 days) trimester of pregnancy, at a time of delivery and postpartum (8 weeks postpartum). Blood samples will be collected and the concentration of bupropion and OH-bupropion in plasma will be determined.